Today, Itogami Island was destined for chaos.
Even more chaotic than during the Harurouin Festival, when the entire city was engulfed in spatial distortions.
"Buzz!"
Amidst the trembling of the atmosphere, beneath the magical array of Tartarus Rose, an enormous magic circle no less magnificent than the one above began to spin on the land of Itogami Island, manifesting in this world.
Unlike Tartarus Roses' rotating magic array, this one didn't spin. Instead, it opened like an immense gate, bursting with dazzling light.
And from within that light, countless monsters emerged.
"Roar!"
It was the frenzied roar of bipedal wyverns.
"Roar!"
This was the roar of true dragon species, so mighty that even bipedal wyverns bowed before them.
"Screech!"
"Howl!"
"Roar!"
These were the cries of various phantasmal species, yokai, and monstrous beings.
In addition, countless other beings from legend and myth appeared, leading the monster army of Aincrad, pouring forth from the gate-like magic array into this world.
They howled madly.
They roared with excitement.
Then, as though provoked, they shot into the sky, soaring toward Rose's direction like an unstoppable tide of warhorses.
Beneath the Rose, the countless summoned Beast Vassals were likewise provoked, unleashing their angry roars as they descended in retaliation.
Two opposing magical arrays—one in the sky, one on the earth—used Itogami Island as their battleground. They ceaselessly summoned all manner of monsters, who met midair and clashed in a titanic battle.
"Boom!" "Boom!" "Boom!" "Boom!" "Boom!"
Explosions thundered through the sky.
"Bang!" "Bang!" "Bang!" "Bang!" "Bang!"
The sounds of destruction rang out without pause.
Monsters fought madly, turning the world around them into a battlefield.
The residents of Itogami Island, already thrown into panic and fleeing from the Beast Vassals, froze in shock as they witnessed this spectacle.
Those who had been running in fear were equally stunned, their expressions darkening.
No one knew what had happened.
No one understood the cause behind it.
But that no longer mattered.
What mattered was that the fierce clashes brought unprecedented devastation to Itogami Island.
"Boom!"
A blast of fire breath rained down, obliterating city streets.
"Thud!"
A massive Beast Vassal was blown from the sky, crashing into a building and flattening it.
The decisive battle between countless monsters brought destruction to every corner of the island.
People could only scream and flee, helplessly caught in a nightmare, sinking into despair.
This was exactly the chaos that Tartarus Lapse had sought to unleash.
However, the fact that Rododaktylos had met its match came as a shock to the opposition as well.
"W-What is that...!?"
In a warehouse in the East District, Rahn seemed to witness everything through surveillance and was visibly shocked.
"How can this be..."
Senga Takehito widened his eyes, staring at the massive ground-based magic array that rivaled the one in the sky and endlessly summoned monsters. His face was filled with dread.
"You..."
December was also stunned, looking at Rozen with disbelief.
But Rozen, after activating the summoning magic array, raised his hand without a word.
"Regulus Aurum!"
Rozen once again summoned the thunderous golden lion.
"Roar!"
With a fierce roar, the thunder-lion appeared, seemingly enraged by its previous loss of control. It glared at December and charged with countless bolts of lightning.
"Dabih Kryastalos!"
December recovered and hurriedly called upon her Beast Vassal, causing the crystal dragon's eyes to shimmer.
Transparent, formless mana surged toward the golden lion, attempting to control it as before.
However...
"Roar!"
With a thunderous roar, the lion repelled the invisible force.
"What?" December gasped in disbelief. "It resisted my control!?"
Yes.
The golden lion had resisted December's control.
And this was entirely natural.
"Did you really think you could control my Beast Vassals?" Rozen said coldly. "Perhaps your Beast Vassal's ability can even control Primogenitor's, but unfortunately, you chose the wrong opponent."
Though Dabih Kryastalos appeared invincible with its ability to control any Beast Vassal, it had weaknesses.
First, the stronger and more numerous the targets, the greater the mana consumption. Exceeding that limit would cause failure or even backfire on the user.
Second, if the opponent's control over their Beast Vassals exceeded that of the controller, it would also fail.
These were the two key flaws of Dabih Kryastalos.
And Rozen not only surpassed December in strength and mana, but his mastery over Beast Vassals was unmatched. As an unparalleled summoner, Rozen had never lost in terms of summoning, commanding, or controlling magical creatures.
Not to mention, his Beast Vassals were bound to him through absolute contracts. They obeyed him completely—even under external control, he could override it with his absolute will.
In short, from the very beginning, December could never control Rozen's Beast Vassals.
She had only succeeded earlier because Rozen had not actively commanded his Beast Vassals, letting them act freely.
Thus...
"You said if I want to stop Tartarus Lapse, I'll have to go through you first?"
Rozen took a deep breath and looked at December.
A chilling glint flickered in his eyes, one that made December's heart skip a beat.
"Originally, I wanted to talk to you. After all, you're Avrora's only remaining kin in this world. But now, I've changed my mind."
Rozen declared.
"You first attacked Kojou, then assaulted Asagi. If you want to die that badly, I'll gladly oblige — Regulus Aurum!"
At Rozen's command, the golden lion roared and lunged at December with a thunderous charge.
"...!"
December retreated several steps, hastily directing her sea dragon to control the nearby Beast Vassals and intercept the golden lion.
"Boom!"
Lightning exploded, echoing like a deafening thunderclap across the heavens.
The golden lion's charge vaporized countless Beast Vassals, erasing them under direct strikes of lightning.
"December!"
Watching all this, Senga Takehito could no longer stay still and tried to step in.
But someone stopped him.
"Senga Takehito, by the authority of a state special attack mage, I hereby place you under arrest!"
Himeragi Yukina stepped forward, raising Sekkaro, and announced sternly.
"Don't get in my way!"
Senga Takehito glared at Yukina, mana surging from his body.
At the same time, Avrora also made her move.
"Come forth! Twelfth Beast Vassal — Alrescha Glacies!"
Avrora summoned the frostbird, manifesting the Twelfth Beast Vassal.
In an instant, frost spread across the entire world.